Method and apparatus for rinsing a microscope slide

ABSTRACT

A method and apparatus for an automated biological reaction system is provided. In the processing of a biological reaction system, there is a need for consistently placing an amount of liquid on a slide. In order to accomplish this, several methods are used including a consistency pulse and a volume adjust means. Moreover, in order to reliably operate an automated biological reaction system, the dispenser must be reliable, easy to assemble and accurate. Among other things, in order to accomplish this, the dispense chamber is substantially in line with the reservoir chamber, the reservoir chamber piston is removed, and the flow of liquid through the dispenser is simplified. Further, in order to operate the automated biological reaction system more reliably, the system is designed in modular pieces with higher functions performed by a host device and the execution of the staining operations performed by remote devices. Also, to reliably catalog data which is used by the automated biological reaction system, data is loaded to a memory device, which in turn is used by the operator to update the operator&#39;s databases. The generation of the sequence of steps for the automated biological reaction device based on data loaded by the operator, including checks to determine the ability to complete the run, is provided.

NOTICE REGARDING COPYRIGHT

A portion of the disclosure of this patent document contains mattersubject to copyright protection. The copyright owner has no objection tothe facsimile reproduction by anyone of the patent disclosure documentas it appears in the Patent and Trademark Office files and records butotherwise retains all copyrights whatsoever.

BACKGROUND OF THE INVENTION

A. Field of the Invention

This invention relates to biological reaction systems, and moreparticularly relates to a method and apparatus for an automatedbiological reaction system.

B. Description of Related Art

Immunostaining and in situ DNA analysis are useful tools in histologicaldiagnosis and the study of tissue morphology. Immunostaining relies onthe specific binding affinity of antibodies with epitopes in tissuesamples, and the increasing availability of antibodies which bindspecifically with unique epitopes present only in certain types ofdiseased cellular tissue. Immunostaining requires a series of treatmentsteps conducted on a tissue section mounted on a glass slide tohighlight by selective staining certain morphological indicators ofdisease states. Typical steps include pretreatment of the tissue sectionto reduce non-specific binding, antibody treatment and incubation,enzyme labeled secondary antibody treatment and incubation, substratereaction with the enzyme to produce a fluorophore or chromophorehighlighting areas of the tissue section having epitopes binding withthe antibody, counterstaining, and the like. Each of these steps isseparated by multiple rinse steps to remove unreacted residual reagentfrom the prior step. Incubations are conducted at elevated temperatures,usually around 40° C., and the tissue must be continuously protectedfrom dehydration. In situ DNA analysis relies upon the specific bindingaffinity of probes with unique nucleotide sequences in cell or tissuesamples and similarly involves a series of process steps, with a varietyof reagents and process temperature requirements.

Automated biological reaction systems include the biological reactionapparatus and the dispensers for the reagents and other liquids used inthe biological reaction apparatus. As disclosed in U.S. Pat. No.5,595,707, inventors Copeland et al., entitled Automated BiologicalReaction Apparatus, assigned to Ventana Medical Systems, Inc. which isincorporated herein by reference, the biological reaction apparatus maybe computer controlled. However, the computer control is limited in thatit is dedicated to and resident on the biological reaction apparatus.Moreover, the memory, which is used in conjunction with the computercontrol, contains data relating to the reagents including serial number,product code (reagent type), package size (250 test), and the like.

One of the requirements in a biological reaction system is consistencyin testing. In particular, the biological reaction system should apply apredetermined amount of liquid upon the slide in order to consistentlytest each slide in the automated biological reaction apparatus.Therefore, an important focus of a biological reaction system is toconsistently and efficiently apply a predetermined amount of liquid onthe slide.

Further, as disclosed in U.S. Pat. No. 5,232,664 entitled LiquidDispenser by inventors Krawzak et al. and assigned to Ventana MedicalSystems, Inc., which is incorporated herein by reference, reagents mustbe dispensed on the slide in precise amounts using a liquid dispenser.The liquid dispenser, which is used in conjunction with the biologicalreaction apparatus, should be easy to manufacture, reliable and compactin size.

SUMMARY OF THE INVENTION

In accordance with a first aspect of the invention, a method andapparatus for consistently placing an amount of liquid on a slide isprovided. In accordance with a second aspect of the invention, a newdispenser for the automated biological reaction system is provided. Inaccordance with a third aspect of the invention, the automatedbiological reaction system which is modular in design is provided. Thesystem is composed of a host device and at least one remote device. Inaccordance with a fourth aspect of the invention, a method and apparatusfor transferring data relating to dispensers used in the automatedbiological reaction system is provided. Data is loaded to a memorydevice, which in turn is used by the operator to update the operator'sdatabases. In accordance with a fifth aspect of the invention, thegeneration of the sequence of steps for the automated biologicalreaction device is provided. The sequence of steps is based on dataloaded by the operator.

Accordingly, a primary object of the invention is to provide anautomated biological reaction system which is modular in design.

Another object of the invention is to provide an automated biologicalreaction system which provides for a means of automatically downloadingdata relating to the reagents including serial numbers, reagent types,lot numbers, expiration dates, dispenser type, and the like in anefficient and reliable manner.

Another object of the invention is to provide an automated biologicalreaction system which consistently and efficiently applies apredetermined amount of buffer upon the slide to which a precise volumeof reagent can be added upon the slide.

A further object of the invention is to provide a liquid dispenser,which is used in conjunction with the biological reaction apparatus,which is reliable.

Yet a farther object of the invention is to provide a liquid dispenser,which is used with a wider array of chemistries in conjunction with thebiological reaction apparatus, which is easy to manufacture.

Still another object of the invention is to provide a liquid dispenser,which is used in conjunction with the biological reaction apparatus,which is compact in size.

These and other objects, features, and advantages of the presentinvention are discussed or apparent in the following detaileddescription.

BRIEF DESCRIPTION OF THE DRAWINGS

A presently preferred embodiment of the present invention is describedherein with reference to the drawings wherein:

FIG. 1 is a left front, isometric view of the automated biologicalreaction system according to a first embodiment of this invention;

FIG. 2 is an exploded right front isometric view of the system shown inFIG. 1;

FIG. 3 is a partial exploded left front isometric view of the systemshown in FIG. 1;

FIG. 4 is a partial exploded right rear isometric view of the apparatusshown in FIG. 1;

FIG. 5A is a block diagram of the modularity of the host and remotedevices of the automated biological reaction system;

FIG. 5B is a format of the addressing for the host devices and remotedevices described in FIG. 5A;

FIG. 5C is a communication transmission protocol between the host deviceand remote devices described in FIG. 5A;

FIG. 6A is an expanded block diagram of the remote device in FIG. 5A;

FIG. 6B is a circuit board connection diagram for the microcontoller;

FIG. 7A is a block diagram of the dual rinse and volume adjustcomponents of the remote device in FIG. 6A;

FIG. 7B is a perspective view of the dual rinse top and dual rinsebottom, volume adjust/coverslip, airknife/barcode blowoff and vortexmixers;

FIG. 8A is a side isometric view of one embodiment of the dual rinse topnozzle and dual rinse bottom nozzle as shown in FIG. 7A;

FIG. 8B is a side view of the angle of the dual rinse top nozzle asshown in FIG. 8A;

FIG. 8C is a side view of the angle of the dual rinse bottom nozzle asshown in FIG. 8A;

FIG. 8D is a side view of one embodiment of the volume adjust as shownin FIG. 7A;

FIGS. 9A-C are a flow chart of the dual rinse, the consistency pulse andthe volume adjust steps;

FIGS. 10 and 11 illustrate the mounting of a liquid dispenser on areagent tray and the manner in which a reagent tray is engaged with adrive carousel;

FIG. 12A is an elevational cutaway view of a prefilled liquid dispenserin the extended position;

FIG. 12B is an elevational cutaway view of a user tillable liquiddispenser in the extended position;

FIG. 12C is an elevational cutaway view of a prefilled liquid dispenserin the compressed position;

FIG. 13A is a cutaway view of the ball chamber and nozzle;

FIGS. 13B and 13C are front and side cutaway views of the lower portionof the barrel with an extension section;

FIG. 14A is an exploded view of an elevational cutaway of a prefilledliquid dispenser;

FIG. 14B is an exploded view of an elevational cutaway of a usertillable liquid dispenser;

FIG. 15A is a side view of a prefilled liquid dispenser;

FIG. 15B is a side view of a customer fillable liquid dispenser withflip top;

FIG. 16A is a cutaway view of the cap and vent of a prefilled liquiddispenser according to one embodiment;

FIG. 16B is an underside view of the cap and vent of FIG. 16A;

FIG. 16C is a cutaway view of the cap and vent of a prefilled liquiddispenser with a bi-directtional duckbill valve;

FIG. 16D is a cutaway view of the cap and vent of a prefilled liquiddispenser with a uni-directtional duckbill valve;

FIG. 16E is a cutaway view of the cap and vent of a prefilled liquiddispenser according to another embodiment;

FIG. 17A is a cutaway view of the lower portion of the barrel, duckbill,duckbill insert, quad seal, check ball, check ball insert and coupler ofa liquid dispenser;

FIG. 17B is a cutaway view of the lower portion of the barrel, duckbill,and duckbill insert of a liquid dispenser;

FIG. 17C is a cutaway view of the quad seal of a liquid dispenser;

FIG. 18 is an alternative embodiment of a cutaway view of the lowerportion of the barrel, duckbill, duckbill insert, quad seal, check ball,check ball insert and coupler of a liquid dispenser;

FIG. 19 is a cutaway view of a syringe with a restrictor for use in thenozzle of the coupler;

FIG. 20 is a block diagram of the manufacturer's system for programmingan external memory device;

FIGS. 21A-B are a flow chart for updating the forms on themanufacturer's reagent database;

FIGS. 22A-B are a flow chart for updating the master lot on themanufacturers reagent database and for inputting data into a memorydevice;

FIG. 23 is a flow chart for downloading data from a memory device to thehost system;

FIGS. 24A-B are a flow chart for updating the memory devices of the userthrough information downloaded from an external memory device;

FIG. 25 is a flow chart for determining if the kit/dispensers for use bythe operator is the correct number and correct complement;

FIGS. 26A-G are a flow chart of a preparation for a run using thedispense table; and

FIG. 27 is a flow chart of the testing run for the remote device.

DETAILED DESCRIPTION OF THE PREFERRED AND ALTERNATIVE EMBODIMENTS OF THEINVENTION

The automated immunostaining system of this invention performs all stepsof immunohistochemical irrespective of complexity or their order, at thetime and temperature, and in the environment needed. Specially preparedslides containing a bar code identifier and a mounted tissue section areplaced in special supports on a carousel, subjected to a preprogrammedsequence of reactions, and are removed from the carousel, ready forexamination. For purposes of clarity of the following description of theapparatus of this invention and not by way of limitation, the apparatuswill be described in terms of immunohistochemical processes.

FIG. 1 is front right isometric view of the automated biologicalreaction system with a host device 32 and one remote device 166. Theremote device 166 includes a staining module 167, bulk fluid module 230and the host device 32 includes a host computer 33, a monitor 34, akeyboard 35 and a mouse 37. FIG. 2 is a front right isometric view ofthe staining module which is part of the automated biological reactionsystem. Liquid and air supply tubing and electrical wiring connectingthe respective components are conventional, well known in the art, andare omitted from the drawings for purposes of clarity.

The apparatus has an upper section 2, intermediate section 4 and lowersection 6. In the upper section 2, reagent tray 10 which supports thereagent liquid dispensers 12 is mounted for rotation about its centralaxis 7 on reagent carousel 8. The reagent carousel 8 and slide carousel24 are circular in the preferred embodiment, but can be any shape whichallows integration with other components in the system. Reagent liquiddispensers 12, described herein with respect to FIGS. 10-18, requiredfor the immunohistochemical reactions to be conducted during slidetreatment cycle are supported by the reagent tray 10, mounted in reagentliquid dispenser receptors 11. These receptors 11 are configured toreceive reagent liquid dispenser. The receptors 11 are preferablyequally spaced in a circular pattern axially concentric with thecarousel axis 7. The number of receptors 11 provided should besufficient to accommodate the number of different reagent liquiddispensers 12 required for a cycle or series of cycles. Twenty-fiveliquid dispenser receptors 11 are shown, but the number can be smalleror greater, and the diameter of the reagent tray 10 can be increased toaccept a larger number of reagent liquid dispensers 12. The reagentcarousel 8 is rotated by the stepper motor 14 drive belt 16 to aposition placing a selected reagent liquid dispenser 12 in the reagentdeliver position under the air cylinder reagent delivery actuator 18over a slide to be treated with reagent.

The intermediate section 4 comprises a vortex mixing plate to which the4 of the 6 mix blocks are attached, the remaining two mix blocks beingmounted on the lower section. The lower section 6 comprises supportplate 22 upon which the slide carousel 24 is rotably mounted. The slidecarousel 24 supports slide supports 26. Heated air is supplied to theapparatus via a resistive heating element and a blower. The heated airrecirculates within the apparatus as shown in FIG. 3. The support plate22 also supports a remote device microcontroller 36 on the automatedbiological reaction apparatus, power supply 24 and liquid and pneumaticvalues. The remote device microcontroller printed circuit board 36, asdescribed subsequently, is generally a processor and can be replaced bya standard computer. The remote device microcontroller printed circuitboard 36 interfaces, via an RS-485 line, with a host device 32, asdescribed subsequently in FIGS. 5A-5C. The lower section 6 includessupport plate 40 upon which are supported accessories such as powersupply 42 and buffer heater 44.

In the lower section 6, the stepper motor 48 rotates the slide carousel24, engaging drive belt 25 engaging the drive sprocket of the slidecarousel 24. The annular waste liquid sump 58 surrounds the shroud 54and is supported on the bottom of plate 22. The waste reagent and rinseliquids are collected in the sump and passed to a drain through anoutlet tube in the sump bottom (not shown).

Rinse and Liquid Coverslip™ (which is light oil substance used toprevent evaporation of the aqueous solutions on the slide) spray blocks60 are supplied with liquid through conventional solenoid valves 62 (seealso FIG. 6A, 248F-J). Buffer heater temperature sensor 66, mounted onbuffer heater 44, controls the heat energy supplied to the buffer heater44. Slide temperature monitoring sensor 68, mounted on support plate 22,control the temperature of the air in the apparatus by controllingenergy supplied to annular heater elements 27. Power supply 42 providespower to the stepper motors 14, 48 and control systems. FIG. 4 is a leftfront isometric view of the bulk fluid module system 230 which isincluded in the automated biological reaction system 150. The bulk fluidmodule 230 includes an air compressor 232, a pressure relief valve 238,cooling tubing 231, a water condenser and filter 234, an air pressureregulator 236, a bottle containing wash buffer 246, and a bottlecontaining Liquid Coverslip™ 244. The air compressor 232 providescompressed air which is regulated by the pressure relief valve (prv) 238to 25 psi. The air passes from the compressor 232 through the coolingtubing and enters the condenser and filter 234. From the condenser andfilter 234, the air passes to the pressure regulator 236. The pressureregulator 236 regulates the pressure to 13 psi. The air, maintained at13 psi, is supplied to the wash buffer bottle 246 and the LiquidCoverslip™ bottle 244 and the staining module 167 (see FIG. 2). Watercondensing out of the compressed air passes out of the condenser andfilter through the pressure relief valve and exits the bulk module. Washbuffer and Liquid Coverslip™ are supplied to the staining module.

Referring to FIG. 5A, there is shown a block diagram of the automatedbiological reaction system 150. The automated biological reaction system150 is segmented into a host device 32, which includes a typicalpersonal computer, and at least one remote device 166, which includesthe automated biological reaction device in FIGS. 1-4. In the preferredembodiment, there are up to eight remote devices 166 which communicatewith the host device 32. Each remote device 166 on the network has aunique address so that each remote device 166 may identified andindividually controlled by the host device 32. As described subsequentlyin FIG. 5B, the automated biological reaction system 150 can support upto eight remote devices 166 due to the 3 bits (values 0-7) dedicated tothe addressing of the remote devices 166. A rotary switch is provided onthe remote device 166 to allow for the identification and the changingof the 3 bit address for each remote device 166. All host messagesincludes this address in them, as described subsequently in FIG. 5B.However, the number of remote devices 166 can be smaller than eight,depending on the capacity requirements or practical limitations of thelaboratory in terms of space. Moreover, the remote devices 166 may beimmunohistochemistry staining modules or another type of instrument thatperforms a different type of staining.

Communication between the host device 32 and the remote devices 166 isaccomplished using a serial RS-485 link, which serves as a network, thatsupports one host and up to 32 remotes at one time. In the preferredembodiment, addressing of the remote devices 166 allows up to 8 remotesdevices to communicate with the host at one time. The RS-485 link has atleast two pairs of lines for communication, one pair for transmittingand one pair for receiving. The remote devices 166 which are connectedto the network "hear" the host messages but do not "hear" other remotemessages. In the preferred embodiment, all communications begin with ahost message, followed a short time later by a response by a remotedevice 166 if present. If the host device 32 sends a message and thereis no remote device 166 to respond to it, the host device 32 times out.In this manner, the communication provides a simple, collision-free linkbetween the host device 32 and the remote devices 166. In an alternativeembodiment, the remote devices 166, in addition to communicating withthe host device 32, address each other. For example, the remote devices166 address each other using the unique 3 bit address, sendinginformation about staining runs, which are described subsequently.

As shown in FIG. 5A, the host device 32 is a typical personal computerwith a processor 152 which includes a comparator 154 for comparingvalues in the processor. The processor 152 is also in communication withmemory devices 156, including non-volatile memory devices such as a ROM158, volatile memory devices such as a RAM 160, and a hard disk 164which contains databases or look-up tables 164. The remote device 166includes a processor, such as a microcontroller 36 wherein themicrocontroller 36 has a comparator 170 for comparing values in themicrocontroller 36. In an alternative embodiment, the microcontroller 36in the remote device 166 is replaced by a personal computer. Themicrocontroller 36 is manufactured by Dallas Semiconductor, model numberDS2251T 128K Soft microcontroller module. The microcontroller 36 has twolines (serial to PC, serial to next inst) to facilitate communicationbetween the host and the remote devices. As shown in FIG. 5A, the hostdevice 32, through the processor, is connected to the serial to PC pinof the microcontroller 36 of remote device 1 (166). The serial to nextinst line of the microcontroller 36 of remote device 1 (166) isconnected to the serial to PC pin of remote device 2 (166). Theconnections follow similarly through remote device N (166). In thepreferred embodiment, there are up to 8 remote devices on the network.In order to terminate the network with the correct impedance in order toavoid any pulse reflections on the network, the serial to nextinstrument line is connected to a terminator 171. The terminator 171 canthereby match the impedance of the network. In the event that one of theremote devices on the network must be removed from the network, theserial to PC line and the serial to next remote device line need only beconnected to each other for the remote device 166 to be removed from thenetwork. Thereby, the network does not "see" that remote device 166 andis effectively removed from the network.

Referring to FIG. 5B, there is shown a format of the addressing for thehost and remote devices 166 described in FIG. 5A. Both the host device32 and the remote devices 166 have the same format and aredistinguishable from one another only by the messages in their fields.Both the host device command and the remote device response for a givenmessage transaction contains the same message. The first character isthe start of message character. The 8th bit is always set to 1, thelower 3 bits contain the address of the remote and bits 3-6 are unused.The host device 32 addresses the remote device 166 in this manner. Theaddressed remote responds in kind with its own address here.

The message length is 2 characters in length. This number indicates thenumber of characters in the entire message. This includes the start ofmessage character and the message checksum character. This is the actualnumber of characters transmitted as seen through the host/remote serialports. The message ID is one character in length. It tags a message witha number (1-255) that identifies it from other messages. The message IDprovides identification for message acknowledges from the remote andprovides safe message retry processing in the remote. The message ID isimplemented by incrementing a number until it reaches 255, andthereafter returning to 0. Each successful message transmission causesthe message ID to increment by 1. Retransmitted messages from the host,due to unsuccessful acknowledgments from the remote, are repeated withthe same message ID as the original message. The message command is 1character in length. For host messages, the message command indicates tothe remote the type of command the message command data pertains to. Forremote messages, this field is used to tell the host device 32 how therequest was received. The message command data is of variable length. Itcontains additional message data, depending on the particular hostcommand. The size of the message command data is dictated by the messagelength, described previously. After removing the other fields fromaround this field, the remainder is the message information. Sincemessage commands may not require message command data, this field maynot always be used. The message checksum is 1 character in length. Itcontains the computed checksum of all characters in the message,starting with the start of message character and including all messagecharacters up to, but not including, this checksum field. No message isprocessed if the message checksum does not match the actual computedchecksum of the received message.

Referring to FIG. 5C, there is shown a communication transmissionprotocol between the host device 32 and remote devices 166 described inFIG. 5A. Messages are downloaded from the host device 32 to the remotedevices 166. The host device initiates a message to send to a remotedevice (172). The host device allocates memory to hold a message 176 andloads the message into memory 178. The host device 32 then places themessage at the top or at the bottom of the queue 180, 182, depending onthe priority of the message. Since the queue is first-in-first-out, themessages at the bottom of the queue go out first. Therefore, if amessage must be sent out immediately, it is placed at the bottom of thequeue 180. Otherwise, if it is an routine status message, the message isplaced at the top of the queue 182. Thereafter, the messages are sent tothe message queues for each of the up to eight remote devices 184, 186,188, 190, 192, 194, 196, 198.

Ordinarily, when a message is sent from the host device 32 to a remotedevice 166, messages are sent periodically through use of a timer. Whenthe host device 32 determines that a message needs to be sent rapidly174, the timer is turned off 200 and all of the messages from thespecific queue as indicated by the host are sent 202. If the host device32 determines that the message does not need to be rapidly sent, themessage is sent in the predetermined sequence based on the timer bysending the next remote in order 206. The host uses the tab position 204which indicates which remote to send the message to.

Referring to FIG. 6A, there is shown an expanded block diagram of theremote device 166. As discussed previously, the remote device 166includes a microcontroller 36. The microcontroller 36 has a user switchand LEDs line which connects to the status PCB (printed circuit board)294. The status PCB 294 is the interface to the user for the remotedevice 166 and includes three LEDs (light emitting diodes) for powerdetermination, error notification and notification of a run in progress.The status PCB 294 also includes a switch, such as a push-button switch,which is used for testing of various functions. When the push-buttonswitch 295 is depressed, the microcontroller 36 executes the lastinstruction that was entered in the microcontroller 36. In this manner,the operator may test the last instruction by simply depressing thebutton 295 rather than going to the host device 32 (which may be in adifferent location) and resending the last command.

The microcontroller 36 also has a slide fan out connection which is usedto control the blower fan 4. The blower fan 4 recirculates air to heatthe slides on the slide carousel 24 of the remote device 166 by forcingair over the heater 302 and then over the slides. The slide temp inconnection is connected to the slide temperature monitoring sensor 68which senses the temperature of the air. The slide temperaturemonitoring sensor 68 is positioned in the path of the heated air andthereby sends information to the microcontroller 36 when to turn theslide heater 302 on and off The slide heater out connection is connectedto the slide heater 302 which, as discussed previously, heats the air inorder to elevate the temperature of the slides. As discussedsubsequently, the host device 32 downloads to the remote device 166 boththe sequence of steps in a run program, and the sensor monitoring andcontrol logic called the run rules. One of the environmental parametersis the upper and lower limit of the air temperature of the slides (usedfor heating the slides). If, during a run, the environmental temperatureis below the lower limit, as indicated by slide temperature monitoringsensor 68, the slide heater 302 is turned on. Likewise, if theenvironmental temperature is above the upper limit, as indicated byslide temperature monitoring sensor 68, the slide heater 302 is turnedoff The power supply 24 supplies both 24 VDC and 5 VDC to the applicable24 VDC and 5 VDC connections. The 24 Volt power supply 24 is used topower the motors 14, 48 which move the slide carousel 24 and the reagentcarousel 8 and the valves 248A-J, which are described subsequently. The120 VAC input is sent through a power switch 310, a fuse 308 and afilter 306 to the AC In connection of the power supply 24. The 120 VACinput is also used to power the slide heater 302, buffer heater 44 andcompressor 232 of the bulk fluid module, which are describedsubsequently. The serial to PC line and the serial to next remote deviceline are described with reference to FIG. 5A. The tub overflow in linereceives input from a conductivity sensor 255 which senses the level ofthe waste in the tub 254. When the conductivity sensor 255 senses thatthe waste line is above a redetermined level, the conductivity sensor255 notifies the microcontroller 36, which in turn ends a status messageto the host device 32. The operator is first given an opportunity toclear the waste from the tub 254. If the tub 254 is still above thepredetermined level, the run is stopped.

The buffer heater 44 is used to heat the wash buffer before it is placedon the slides since it has been determined that better results areachieved by heating the wash buffer to the temperature of the tissue onthe slide. The buffer heater 44 consists of a cast aluminum block 249with a spiral tubing 251 inside the block. When the wash buffer flowsthrough the tubing 251 through the block 249, the temperature of thewash buffer will be the temperature of the aluminum block 249 upon exitfrom the tubing 251. In order to control the temperature of the block, abuffer heater temperature sensor 66 is used which is physically placedon the aluminum block 249. The microcontroller 36 receives the buffertemperature sensor input via the buffer temp line and can therebycontrol the temperature of the buffer heater 44 by turning on and offthe buffer heater 44 via the buffer heater line on the PCBmicrocontroller 36.

The liquid valves 248A-J for the Liquid Coverslip™ and the wash bufferare controlled by the liquid valve connections. There is a separate pairof wires (power and ground) for each valve 248A-J shown in FIG. 6A whichare omitted for ease of display. Each valve 248A-J is a relay which isactivated by the microcontroller 36 by energizing the relay. The volumeadjust 266, dual rinse top 263, and two dual rinse bottom 264 deviceswill be described subsequently in FIGS. 7-9. Further, there is a slidedoor optical sensor 258 which is input to the slide door switch in lineconnection and which is used to determine if the front door of theremote device 166 is open. This sensor 258 is used for safety reasons sothat, if the front door is open and remains open for five minutes, theslide carousel 24 does not move. Moreover, there is a second opticalsensor, the upper level optical sensor 262, which is used to determineif the upper chassis on the remote device 166 has been opened.

Further, as shown in FIG. 6A, the dispense cylinder 282 uses thedispense cylinder extend and the dispense cylinder retract so that thedispense plunger extends and retracts the liquid dispensers. Using airvia the system air line, the dispense cylinder 282 is pushed out byusing the dispense cylinder extend line. The microcontroller 36 controlsthe air valves 248A, 248B so that the relay corresponding to thedispense cylinder extend line is activated. In this manner, the dispensecylinder 282 pushes the liquid dispenser down, as described subsequentlyin FIGS. 12A-12C, thereby dispensing reagent. In order to retract thedispense cylinder 282, the dispense cylinder retract valve 248B isactivated using the system air line so that the liquid dispenser ispushed to retraction. Additionally, an extension spring is used to helpspeed the retraction process, as described subsequently. An opticalsensor is used to determine if the dispense is extended, and therebyactivated. When the dispense cylinder 282 is extended, the opticalsensor is tripped validating that the dispense operation has occurred.Motors 14, 48 move the slide carousel 24 and the reagent carousel 8 andare connected to the slide motor out connection and the reagent motorout connection, respectively. The motors 14, 48 are typically steppermotors.

Sensors 274, 286 are placed in proximity to the slide carousel 24 andthe reagent tray in order to determine the "home" position of each. Inthe case of the slide carousel 24, the slide carousel home sensor 274 isinductive-type and senses a piece of metal placed underneath the slidedesignated as the "home" position. When the "home" position is found,the sensor 274 sends a signal to the slide home in line of themicrocontroller 36. In the case of the reagent tray 10, the sensor 286also is an inductive-type of sensor. The reagent tray 10 has a largeflat metal ring around the entire tray except for the home position. Inthis manner, when the sensor 286 senses an absence of metal, this isdetermined to be the home position thereby indicating to themicrocontroller 36, via the reagent home in connection, that the homeposition is found. The sensor 286 senses the reagent tray 10, ratherthan the reagent carousel 8, since the user may remove the reagent tray10. Additionally, since the sensor 286 looks for the absence of metalfor the home position, the absence of the reagent tray 10 may be testedby looking for the absence of metal in two consecutive positions.

System pressure is determined via the system air line which directlyfeeds into a transducer 290. The transducer 290 generates an analogvoltage which is proportional to the pressure. The output of thetransducer 290 is then sent to an analog to digital converter (ADC) 292whose output is sent to the microcontroller 36 via the system pressurein connection. Contrary to previous pressure switches which onlyindicated whether the pressure was below a minimum value, the transducer290 and ADC 292 combination indicates to the microcontroller 36 theexact pressure. Therefore, the microcontroller 36 can determine bothwhether the pressure is too low and too high. In either instance, themicrocontroller 36 sends an error message and shuts down the run.

As shown in FIG. 6A, the bulk fluid module 230 includes the compressor232 which pressurizes the air to up to 90 psi. The compressed air issent to a filter 234 in order to filter out the water and othercontaminants. Pressure is regulated in a two-step fashion. First, thepressure is regulated at the compressor to approximately 25 psi (±1 psi)via a spring diaphram (prv) 238. The prv 238 is manufactured by Norgrenin Littleton, Colo., part number NIP-702 with a plastic bonnet. Second,the pressure is fine-tuned to 13 psi using an air pressure regulator236. The pressure regulator 236 is very accurate in terms of precisepressure regulation over long periods of time. In this manner, thecompressor 232 need not overwork itself since the prv 238 maintains thepressure at the output of the compressor to 25 psi by opening andletting out excess pressure when the pressure exceeds 25 psi. Water andparticulates, which are filtered out of the air via the filter 234, aresent to a waste receptacle. The compressed air pressurizes the LiquidCoverslip™ and wash buffer bottles 244, 246 so that when the valves248F-J are opened corresponding to the Liquid Coverslip™, volume adjust,dual rinse top, dual rinse bottom lines, the pressure is already on theline and the liquid may flow. In addition, the compressed air is usedfor the dispense cylinder extend line, the dispense cylinder retractline, the mirror air cylinder line, the vortex mixers line, and the barcode blowoff/airknife line. Filters 240 are used at the outputs of theLiquid Coverslip™ and wash buffer bottles 244, 246 in order to removeparticulates which may get caught in the valves 248.

The mirror air cylinder line is used to turn the mirror cylinder 278 sothat the bar code reader 276 either reads bar codes on the slides of theslide carousel 24 or bar codes on the liquid dispensers on the reagentcarousel 8. The output from the bar code reader 276 is input to themicrocontroller 36 via the bar code serial I/O connection. In betweenthe valve 248C for the mirror air cylinder line and the mirror cylinderis a flow restrictor 268. The flow restrictor 268 slows the flow of airin the line while still maintaining the 13 psi pressure on the line. Inthis manner, this moves the mirror slower than would otherwise be donewithout the restrictor 268.

The vortex mixers 271 likewise operate off of the 13 psi system air lineto mix the contents on the slide. The vortex mixers 271 may be used in asingle stream or in a dual stream mode. In particular, a single streamof air or a dual stream of air may be used to mix the contents on theslide. Further, restrictors 268 are used in the vortex mixers lines inorder to reduce the flow of air. In this manner, when the vortex mixers271 are used to mix the contents on the slide, the liquid does not blowoff the slide and the mixers do not dry any particular spot on theslide.

The bar code blowoff/airknife 267 is used to blow air on the portion ofthe slide which contains the bar code. In this manner, the bar code iseasier to read. Further, liquid can be kept on the slide better due tosurface tension if liquid near the edge of the slide is removed.

Referring to FIG. 6B, there is shown a circuit board connection diagramfor the microcontoller. The sensors and motors for the remote device 166plug into this board which in turn is in communication with themicrocontroller.

Referring to FIG. 7A, there is shown a block diagram of the dual rinseand volume adjust components 263, 264, 266 of the remote device 166 inFIG. 6A. A run is generally executed in a series of steps including thefollowing: reagent is applied to the slide, Liquid Coverslip™ is appliedto the slide, the reagent reacts with the tissue on the slide, adifferent reagent is applied to the slide, Liquid Coverslip™ is appliedto the slide, the different reagent reacts with the slide, etc. Afterthe reagent reacts with the slide, but before the next reagent isapplied to the slide, the excess reagent which did not react with thesample should be removed from the slide. Otherwise, there is thepossibility of having non-specific staining, or background staining, onthe slide. This non-specific staining may interfere with the visualanalysis of the slide at the end of the run. In order to minimize thenon-specific staining, the residual reagent from the previous step iswashed from the sample using a wash buffer. Washing may be achievedusing a dual rinse device which executes a dual rinse step using a dualrinse top valve 248 and a dual rinse bottom valve 248, as shown in FIG.7. The microcontroller 36 controls the valves so that the wash bufferpulses the slide with the dual rinse top valve 248H and one of the dualrinse bottom valves 248I or 248J consecutively. In particular, duringthe dual rinse step, the microcontroller 36 turns on the dual rinse topvalve 248H, then one of the dual rinse bottom valves 248I or 248J, andso on. As described subsequently, there are two dual rinse bottom valves248I or 248J in order to achieve the consistency pulse.

Referring to FIG. 7B, there is shown a perspective view of the dualrinse top and dual rinse bottom, volume adjust/coverslip,airknife/barcode blowoff and vortex mixers. The configuration is in theform of a boomerang whereby the boomerang follows the curved portion ofthe slide carousel 24.

Referring to FIG. 8A, there is shown a side isometric view of oneembodiment of the wash block 312 which employs the dual rinse top nozzle263 and dual rinse bottom nozzle 264 as shown in FIG. 7. The wash block312 comprises a lower set of nozzle outlet openings 316 corresponding tothe dual rinse bottom nozzle 264 and an upper set of nozzle outletopenings 314 corresponding to the dual rinse top nozzle 263. During thedual rinse step, these openings 314, 316 direct streams of pulsed rinsedliquid towards one or the other of the longitudinal edges 322 of theslide 318. The streams of the pulsed rinsing liquid, from each of thelower and upper sets of nozzle outlet openings 314, 316 preferablyimpact the slide 318 at the rinse liquid impact zone 320 which isupstream on the slide 318 from the tissue sample (not shown) positionedthereon. Positioning of the wash block 312 is important due to thefragile nature of the tissue sample positioned on the slide. Bydirecting streams of pulsed rinsing liquid at the impact zone 320 of theslide, the rinse liquid is provided with laminar flow by the time therinse liquid reaches the tissue sample. As a result, undue damage to thefragile tissue sample is prevented.

The upper set of nozzle outlet openings 314 is constructed so that theassociated streams of rinse liquid are off-set at an angle from thelongitudinal center line of the slide so that the pulsed streams ofrinse liquid are directed toward one of the longitudinal edges of theslide 318. The lower set of nozzle openings 316 is constructed so thatthe associated streams of rinsing liquid are also off-set at an anglefrom the longitudinal center line of the slide so that the pulsedstreams of rinse liquid are directed toward the other one of thelongitudinal edges of the slide 318. As a result of this arrangement,pulsed streams of rinse liquid are alternatively and repeatedly directedto one and then the other of the longitudinal edges of the slide.

As shown in FIG. 7, separate plumbing and valving are provided for eachof the lower and upper sets of nozzle outlet openings 314, 316 of thedual rinse top nozzle and dual rinse bottom nozzle 263, 264 to permitindependent operation thereof. In operation of the dual rinse step, thewash block 312 directs streams of pulsed rinsing liquid, for examplefrom the lower set of nozzle openings 316 toward a single longitudinaledge of the slide and after completion then directs streams of pulsedrinse liquid, for example from the upper set of nozzle openings 314, tothe other longitudinal edge of the slide. This procedure is repeated,via control of the valves 248H-J using the microcontroller 36, and hasthe effect of rinsing the previous layer of rinse liquid and chemicalsoff of the slide. The wash block nozzle axis of each of the dual rinsetop nozzle and dual rinse bottom nozzle 263, 264 forms an angle with thehorizontal of between 15 and 35 degrees, preferably substantially 35degrees for the dual rinse top nozzle 263 and substantially 25 degreesfor the dual rinse bottom nozzle 264, as described in FIGS. 8B and 8C.Moreover, the angle of the slide is substantially horizontal (0.5degrees to 1.25 degrees) so that the wash buffer both washes the excessreagents off of the slide and also flows off of the slide.

After cleaning the excess reagent off of the slide, a precise amount ofwash buffer should be applied to the slide. Ordinarily, 270 μL is theoptimal amount of buffer which should be placed on the slide for thenext step. In executing the dual rinse step, there is residual washbuffer on the slide; however, the amount of wash buffer left on theslide varies considerably. In order to consistently leave a specificamount of liquid on the slide, the microcontroller 36 executes aconsistency pulse.

The consistency pulse consistently leaves an amount of liquid on theslide with variation in amount lower than a shorter pulse, and theconsistency pulse cleans the slide of excess reagents. The consistencypulse is a pulse of wash buffer which is executed for a longer period oftime than the individual pulses of the dual rinse step. To send washbuffer onto the slide, the tubing containing the wash buffer ispressurized. Because of this pressure and because of the turning on andoff of the wash buffer valves 248H-J, there is a pressure wave effectgenerated in the wash buffer tubing. Therefore, one cannot consistentlydetermine where one is on the wave. Because of this wave effect, theamount of pressure that the pulse has varies so that the amount ofbuffer left on the slide varies as well. In order to minimize the waveeffect, the consistency pulse turns the valve on for a period ofsufficient time and/or for a sufficient strength in order to let thewave effect minimize within the tubing. The consistency pulse istherefore an extended burst of either the dual rinse top nozzle 263 orthe dual rinse bottom nozzle 264 for a period longer than the dual rinsestep. For example, as describe in FIGS. 9A-C in more detail below, theperiod for a pulse during the dual rinse step is 60 mSec whereas theperiod for the consistency pulse is 300 mSec.

Moreover, in order for the consistency pulse to leave a consistentamount of liquid on the slide, the momentum of the consistency pulseshould be greater than that during the dual rinse step. In the preferredembodiment, the increase in momentum of the pulse is achieved byincreasing the volume of wash buffer flow using two dual rinse bottomvalves 248I and 248J, as shown in FIG. 7, as opposed to using only onedual rinse valve 248I or 248J during the dual rinse step. In thismanner, the stream of wash buffer with an increased momentum is sentacross the slide with the result that the residual volume of buffer lefton the slide after the consistency pulse is lower and also has a lowervariation. If a pulse of lower momentum is used, more solution is lefton the slide due to interaction with the surface tension of the slide.In an alternative embodiment, the increase in volume and subsequentincrease in momentum for the consistency pulse may be achieved using avalve which has an opening which is larger than the opening of thevalves 248H-J used during the dual rinse step. The consistency pulsetherefore has a strong flow out of the nozzle, generating a laminar, notturbulent, flow on the slide. The laminar flow then washes off theslide, consistently leaving an amount of liquid on the slide. Moreover,the consistency pulse is consistent, not only from run to run on anindividual machine, but also from machine to machine as well.

Further, when both a consistent and a minimal amount of buffer isdesired to be left on the slide, the dual rinse bottom nozzle 264 shouldbe used rather than the dual rinse top nozzle 263. The angle of the dualrinse bottom nozzle 264 is less than the angle for the dual rinse topnozzle 263; therefore, the less steep the angle, the more likely thebuffer will flow off of the slide, not interacting with the surfacetension of the slide. For example, using a dual rinse top nozzle 263with a single valve leaves approximately 275±40 μL on the slide whereasusing a dual rinse bottom nozzle 264 with a dual valve leavesapproximately 180±20 μL on the slide.

With varying the time of the pulse, the angle of the pulse, and themomentum, the consistency pulse may be used in several ways. The firstway is for the consistency pulse to leave a minimal amount of washbuffer on the slide with minimal variation from run to run and machineto machine (180±20 μL) for any given instrument. In particular, thisvariation of ±20 μL is across all machines so that, in the event thatone machine must be replaced by a second machine, the variation is smallenough so that the amount of liquid left on the slide is withinacceptable parameters. Moreover, the variation from run to run within asingle machine is approximately ±10 μL so that, once the machine iscalibrated, and the amount of volume dispensed from the volume adjust isdetermined to achieve a total volume of 270 μL, which is discussedsubsequently, the liquid on the slides for a particular machine does notvary significantly run to run.

The modification of the consistency pulse is done by using a time longerthan the individual dual step pulse, the dual rinse bottom nozzle 264,and the two valves 248I and 248J; after the consistency pulse step, therequired amount of buffer on the slide (as determined by the experiment)may be added using the volume adjust 266, which is describedsubsequently, with extreme precision.

Apart from using the consistency pulse to leave a minimal amount ofbuffer on the slide, the consistency pulse may be used to leave anamount greater than a minimal amount while still having a low variationin the amount left on the slide. For example, the operator may adjustthe amount of momentum of the pulse, the angle of the outlet nozzle withrespect to the slide, and the angle of slide with respect to horizontal.As one example, the outlet of the nozzle may be designed with an anglewhich is less than the angle of the dual rinse bottom nozzle. In thismanner, the operator may tailor the amount left on the slide dependingon the amount and variance of the buffer necessary for the experiment.

After the consistency pulse, if additional buffer is necessary to beplaced on the slide to run the experiment, the volume adjust is used, asshown in FIG. 7. The microcontroller 36 turns on the valve 248G for thevolume adjust line to place buffer on the slide. As describedpreviously, the volume adjust line has a restrictor 268 which reducesthe volume flow of the wash buffer through the line. This is done sothat the buffer does not disturb the tissue on the slide since theneedle of the volume adjust nozzle 388 is directly above the slide andthe wash buffer is dropped onto the slide. A precise amount of buffer isable to be placed on the slide. This is based on the amount of pressurein the wash buffer bottle, the amount of time the valve 248G for thevolume adjust line is open, and the amount of flow through therestrictor 268. Based on these parameters, the amount of volume placedon the slide may be adjusted by changing the dial nozzle which controlsthe amount of time the valve for the volume adjust line is open. In thealternative, the amount of time the valve is open may be adjusted usinga potentiometer.

In operation, the volume adjust 266 is more accurate when it is turnedon for more than 60 mSec. Operating the volume adjust 266 less than 60mSec makes the dispensing of the buffer less accurate. Therefore, whendesigning a system which combines both the consistency pulse with thevolume adjust, the consistency pulse should leave a volume of liquid onthe slide low enough so that the volume adjust may be turned on for morethan 60 mSec. In order to accomplish this, the consistency pulse isdesigned to leave a minimal amount of liquid on the slide by using thedual rinse bottom nozzle 264 and the two valves 248I and 248J. Inpractice, after the consistency pulse using the dual rinse bottom nozzle264 and the two valves 248I and 248J, there is 180±20 μL. By turning onthe volume adjust for approximately 100 mSec, the volume on the slide isincreased to approximately 270 μL.

Referring to FIGS. 8B and 8C, there are shown side views of the anglesof the dual rinse top nozzle 263 and dual rinse bottom nozzle 264,respectively, as shown in FIG. 8A. The angle, as described previously,is 35 degrees from the horizontal for the outlet of the dual rinse topnozzle (263) is 25 horizontal for the outlet of the dual rinse bottomnozzle (264). These angles may be varied in order to modify the amountand/or variation of liquid left on the slide after the consistencypulse.

Referring to FIG. 8D, there is shown a side view of one embodiment ofthe volume adjust as shown in FIG. 7. The needle 388 of the volumeadjust is composed of a stainless steel with a 90 degree needle. Fluidtherefore goes at a downward angle and drops onto the slide. Theconnector pieces which connect the needle 388 to the acrylic block 392of the volume adjust are also composed of stainless steel. The stainlesssteel is used since it does not react with the wash buffer. At the backof the acrylic block 392 is a connector 394 which connects to the volumeadjust line of FIG. 6A. At the side of the acrylic block is a connector396 which connects to the Liquid Coverslip™ line of FIG. 6A.

Referring to FIGS. 9A-C, there is shown a flow chart of the dual rinse,the consistency pulse and the volume adjust steps. For the dual rinsestep, one of the dual rinse bottom valves (248I or 248J) is first turnedon 324, the microcontroller 36 waits for 60 mSec 326, and the dual rinsebottom valve (248I or 248J) is turned off 328. The microcontroller 36then delays for 30 mSec 330. The dual rinse top valve (248H) is thenturned on 332, the microcontroller 36 waits for 60 mSec 334, and thedual rinse top valve (248H) is turned off 336. The microcontroller 36then delays for 30 mSec 338. This sequence is repeated two times 340.Then, the microcontroller 36 waits 1100 mSec 342. Then the dual rinsetop valve (248H) is turned on 344, the microcontroller 36 waits for 60mSec 346, and the dual rinse top valve (248H) is turned off 348. Themicrocontroller 36 then delays for 30 mSec 350. One of the dual rinsebottom valves (248I or 248J) is first turned on 352, the microcontroller36 waits for 60 mSec 354, and the dual rinse bottom valve (248I or 248J)is turned off 356. The microcontroller 36 then delays for 30 mSec 358.This sequence is repeated four times 360. Then the dual rinse top valve(248H) is turned on 362, the microcontroller 36 waits for 60 mSec 364,and the dual rinse top valve (248H) is turned off 366. Themicrocontroller 36 then waits 1200 mSec 368.

In the preferred embodiment, the dual rinse step begins with abottom-top, bottom-top rinse cycle, and then a top-bottom, top-bottom,top-bottom, top-bottom rinse cycle. In this manner, the slide is cleanedbetter. This switching of the dual rinse step, starting with one set ofnozzles (in the preferred embodiment, the dual rinse bottom valve), andin the next step, starting with the other set of nozzles (in thepreferred embodiment, the dual rinse top valve), allows for quickercleaning of the slide while using less buffer.

For the consistency pulse step, both the dual rinse bottom valves (248Iand 248J) are turned on 370, 372, the microcontroller 36 then delays 300mSec 374, and both the dual rinse bottom valves (248I and 248J) areturned off 376, 378. For the volume adjust step, after the slidecarousel 24 is moved one position 380, the valve 248G for the volumeadjust line is turned on 382. The microcontroller 36 waits, depending onthe amount of liquid to be deposited on the slide 384. Then, the valve(248G) for the volume adjust line is turned off 386. Delays in betweenthe dual rinse step, consistency pulse step, and volume adjust step areinserted in the steps above in order to minimize the possibility ofhaving too many valves on in the system at the same time. If thisoccurs, this drops the pressure and, in turn, reduces the force ofliquid of wash buffer and Liquid Coverslip™.

FIGS. 10 and 11 illustrate the manner of mounting a liquid dispenser 400in a reagent tray which is engaged in the reagent carousel 8. The foot440 is initially inserted into a circular U-shaped groove 442 formed inthe reagent tray 10. In an alternative embodiment, the foot is insertedinto a rectangular shaped groove. Groove 444 of spring member 448engages a circumferential lip 446 of the reagent tray 10. FIG. 11 showsa cross sectional view of the liquid dispenser 400 after it has beenmounted on the reagent tray 10 showing in particular the manner in whichfoot 440 fits into groove 442 and showing the flexing of spring member448 to hold the liquid dispenser 400 firmly in place. To remove theliquid dispenser 400, spring member 448 is simply bent inward slightlyso that the groove 444 clears the lip 446, and the foot 440 is withdrawnfrom groove 442.

Referring to FIG. 12A, there is shown an elevational cutaway view of aprefilled liquid dispenser 400 in the extended position. FIG. 12B showsan elevational cutaway view of a user fillable liquid dispenser 400 inthe extended position. The main difference between the prefilled andcustomer fillable dispensers is the substitution of a flip cap 402 toreplace the snap cap 404. The liquid dispenser 400 has a reservoirchamber 410, which stores the liquid, and a dispense chamber 412,whereby the reservoir chamber 410 is above the dispense chamber 412. Thereservoir chamber 410 is substantially in line with the dispensechamber, and in the preferred embodiment, coaxial with the dispensechamber 412.

Previous liquid dispensers included a reservoir chamber 410 which was tothe side of the dispense chamber 412 requiring a connecting orhorizontal section which connected the reservoir chamber 410 with thedispense chamber 412. In addition to potential problems of clogging ofthe horizontal section, the previous design was more difficult tomanufacture. In particular, the side-by-side design required that themolding process of the horizontal or connecting piece be carefullycontrolled so that all sides of the connecting piece interact correctlywith the reservoir chamber 410, the dispense chamber 412, and the ballchamber 432 and nozzle 430. As described subsequently, the ball chamber432 includes a check ball 426 which seats in the upper part of the ballchamber 432 during a portion of the operation of the liquid dispenser400. In previous designs, the coupler was formed via a T-shaped chambera horizontal chamber abutting two vertical pieces. At the intersectionof the pieces, the ball seat area was formed. In manufacturing thiscoupler, the consistency of the T-shaped piece varied so that the ballseat area was, at times, difficult to manufacture properly. In thepresent invention, the liquid dispenser 400 requires no horizontal orconnecting portion between the reservoir chamber 410 and the dispensechamber 412. The reservoir chamber 410 is on top of dispense chamber 412and, in the preferred embodiment, the reservoir chamber 410 is coaxialwith the dispense chamber 412. Since the flow is substantially in oneline or vertical, the T-shaped piece is removed. Moreover, the ball seatarea is replaced by a check valve ball insert 424 which is a separateand smaller molded piece and therefore can be controlled, from amanufacturing standpoint, better than in previous designs.

In the preferred embodiment, the reservoir chamber 410 shape is as shownin FIGS. 12A and 12B. The reservoir shape may also be funnel-like or anyother shape which drains the fluid through the connecting means betweenthe reservoir chamber 410 and the dispense chamber 412. The connectingmeans between the reservoir chamber 410 to the dispense chamber 412 inthe preferred embodiment is a valve, such as a duckbill 416 which has ameans to sense pressure differentials. In alternate embodiments, theconnecting means is any device which transfers liquid in one direction(from the reservoir chamber 410 to the dispense chamber 412) and whichpasses liquid based on a pressure differential. This includes using anumbrella valve. Further, in an alternative embodiment as shown in FIG.18, there is shown a barrel 408 which has a lower section which acts asa piston 454 at its lower end, similar to FIGS. 12A-12C; however, theliquid dispenser does not have duckbill valve. Instead, at the lowersection of the barrel, in the piston area, there are holes 450 in theside of the barrel 408 which contact O-ring seals 452. In this manner,when the barrel 408 is pushed downward, the holes 450 are exposed,expelling liquid and dispensing liquid from the reservoir chamber 410.Further, the end of the piston 454A is closed thereby sealing the bottomof the barrel 408 except for the holes 450.

Liquid is ejected from the dispense chamber 412 by exerting a downwardforce on the cap, against the force of the compression spring 418. Thisforces the barrel 408 downward until it reaches the stop 420 whichprevents the barrel 408 from further downward movement, as shown in FIG.12C. When the liquid dispenser 400 is mounted on a reagent tray 10, asdescribed in FIGS. 10 and 11, the downward force on the cap 404 isapplied by the dispense cylinder extend air line, as described in FIG.6A, or by some other means to push the barrel 408 downward. The downwardmovement of the barrel 408, including the lower portion of the barrelwhich acts as a piston, expels liquid from the dispense chamber 412. Inthis manner, problems associated with a piston which is a separate piecein the dispense chamber 412 are avoided.

As the spring 418 expands, the barrel 408 moves upward and the checkball 426 moves upward as well. Referring to FIG. 13A, there is shown adetailed view of the ball chamber 432 and nozzle 430. The coupler 428 isformed where a hole in the coupler is offset for ball chamber 432 sothat an inner edge of nozzle 430 protrudes into the outlet of ballchamber 432. Ball chamber 432 contains a check ball 426 which fitsloosely against the cylindrical surface of ball chamber 432 and is freeto move between an uppermost position and a lowermost position. In itsuppermost position, check ball 426 mates with the check valve ball seat424, thereby preventing liquid flow in the direction from nozzle 430 todispense chamber 412. At its lowermost position, the check ball 426 isrestrained by inner edge of nozzle 430 and prevented from falling intonozzle 430. This does not prevent liquid from flowing from ball chamber432 to nozzle 430, however.

Using the above described structure as a basis, the operation and uniquecharacteristics of liquid dispenser 400 will now be described. At thebeginning of a dispense stroke, the liquid dispenser 400 is in thepositions shown in FIGS. 12A and 12B. When liquid is to be dispensed, adownward force is applied against cap 402. This overcomes the force ofcompression spring 418 and forces the barrel 408 downward until itreaches the seat of the stop 420, thereby dispensing a predeterminedvolume of liquid equal to about 100 μL. This is equal to the liquidvolume of the area that the barrel 408 moves down minus the "suck back"(which is the amount of fluid that travels past the check ball on theupstroke of the barrel 408 before the check ball 426 shuts off theflow). The liquid flows from dispense chamber 412 into ball chamber 432.The downward flow through ball chamber 432 forces check ball 426 to itslowermost position, abutting edge, but this does not prevent flow inthis direction and the measured amount of liquid is ejected from nozzle430.

When the barrel 408 has reached its lower extreme position, the downwardforce on cap 402 is released, by the microcontroller 36 actuating thevalve 248B for the dispense cylinder retract air line, as described inFIG. 6A, and compression spring 418 takes over, forcing barrel 408 andcap 402 in an upward direction. Liquid begins to be sucked into dispensechamber 412, which was described previously as the "suck back."

It is here that the interplay of check valve ball seat 424 and ballchamber 432 is described. Check valve is a duck bill valve 416, whichrequires a predetermined threshold pressure differential in order topermit flow in the forward direction. In contrast, check ball 426 movesfreely within ball chamber 432, and therefore provides essentially noresistance to liquid flow from nozzle 430 until it reaches its sealingposition at the check valve ball seat 424. When the dispenser operationis completed, the liquid flow has forced check ball 426 to its lowermostposition, abutting edge 434. As the upward movement of the barrel 408begins to draw liquid back into dispense chamber 412, the upward flow offluid in ball chamber 432 pulls check ball 426 upward until it reachescheck valve ball seat 424, where it cuts off any further liquid flowtoward dispense chamber 412. Until check ball 426 reaches the checkvalve ball seat 424, however, there is virtually no resistance to liquidflow from nozzle 430, and therefore no pressure differential is createdacross duck bill check valve 416 sufficient to cause liquid flow fromreservoir chamber 410 to dispense chamber 412.

The volume of liquid which flows from nozzle towards dispense chamber412 ("suck back") while check ball 426 is moving from its lowermost toits uppermost position is preselected to be a volume exactly equal tothe volume of the hanging drop left at tip at the end of the dispensecycle. Thus, the drip is effectively drawn back into nozzle 430 and aninternal meniscus forms at tip.

When check ball 426 reaches the check valve ball seat 424, it shuts offurther flow from nozzle 430 into dispense chamber 412. This immediatelycreates a pressure differential across check valve and causes liquid toflow from reservoir chamber 410 into dispense chamber 412. The suctiongenerated in dispense chamber 412 keeps check ball 426 firmly seatedagainst the check valve ball seat 424 and prevents any further flow fromnozzle 430. When compression spring 418 has forced barrel 408 upward, asshown in FIGS. 12A and 12B, the liquid dispenser 400 is ready foranother dispense cycle. Check ball 426, being made of a materialslightly more dense than the liquid, falls through ball chamber 432until it make contact again with edge 434.

Referring to FIGS. 13B and 13C, there is shown a front and side cutawayof the lower portion of the liquid dispenser 400, respectively, in analternative embodiment of the invention wherein the check valve ballseat 424 and check ball 426 are removed. In order to retract a hangingdrop from the edge of the nozzle 430, the piston 454 on the end of thebarrel 408 has an extension piece 456 connected to it. In this manner,when the barrel 408 is raised upward, the extension piece 456 movesupward as well, thereby retracting any drops on the edge of the nozzle430.

Referring to FIGS. 14A and 14B, there are shown exploded views of acutaway of a prefilled and user fillable liquid dispenser 400,respectively. As described previously, the difference between theprefilled and the user tillable liquid dispensers is the snap cap 404,as shown in FIGS. 14A and 14B. Fluid can be filled into the reservoirthrough a fill hole and subsequently closed using a snap cap 404 inorder to close the system. For prefilled liquid dispensers, the snap cap404 is permanently attached over the fill hole after filling. The fillhole and the snap cap 404 are matched using a luer fitting design inorder to be a tight seal, as shown in FIG. 16. The user fillable liquiddispenser 400 utilizes a living hinge design and luer slip designbetween the fill hole and the flip cap 402. The cap 406, as previouslydescribed, is sonically welded to the barrel 408. The cap 406 also has avent 460, which is described subsequently with respect to FIG. 16. Theduckbill insert 414 holds the duckbill 416 in place and creates a sealso that fluid cannot drip either from the dispense chamber 412 to thereservoir chamber 410 or from the reservoir chamber 410 to the dispensechamber 412. Further, the duckbill insert 414 has a protrusion, or anipple, which holds the duckbill to it for ease of assembly, as shown inmore detail in FIG. 17B. The duckbill 416, which serves as a checkvalve, is snapped to the duckbill insert 414. The duckbill valve 416 isa one way valve with a high cracking pressure of between 0.6 to 2.5 psi.This acts to hold the liquid in the reservoir chamber 410 since thecracking pressure is greater than the head pressure of the reservoirchamber 410. And, the duckbill passes fluid from the reservoir chamber410 to the dispense chamber 412 on the upstroke of the barrel 408 whilepreventing liquid to pass during the downstroke of the barrel 408. Theduckbill 416 and duckbill insert 414 are seated in the lower portion ofthe barrel 408 as shown in FIG. 17A.

The spring 418 is a compression spring which expands and contracts basedon the movement of the barrel 408. The stop 420, as describedpreviously, stops the downward stroke of the barrel 408. The stop alsoholds the quad seal 422 in place during movement of the liquid dispenser400. The manner in which the assembly is assemble, the stop 420 is heldin place based on the compression spring 418. The force varies based onthe movement of the barrel 408. The stop 420 is held in place, in turn,keeps the quad seal 422 in place via a ledge 420A, as shown in FIG. 17C,on the stop 420. The quad seal 422 ensures that the liquid dispenser 400is always a closed system thereby keeping the liquid dispenser 400primed. The check valve ball seat 424 is a separate part from thecoupler 428 and is seated inside the coupler 428, being snapped intoplace by grooves in the chamber of the coupler 428 and by being seatedon a ledge 428A, as shown in FIG. 17A. The check valve ball seat 424 hasa ball seat 424A on the inside with which to engage the check ball 426on the upstroke of the barrel 408. Previous liquid dispensers integratedthe coupler with the check valve ball seat for the check ball. However,manufacturing of the coupler integrating those functions was difficult,as described above. Therefore, processing is simplified by separatingthe check valve ball seat 424 from the coupler 428. The inner cavity 432of the check valve ball seat 424, which engages the check ball 426, maythen be manufactured more easily. The check ball 426 is made of aborosilicate (which is a type of glass). In an alternative embodiment, acheck ball 426 composed of rubber may be used. In certain instances, arubber ball may seat better in the plastic check valve ball seat 424,provided there is no chemical interaction of the rubber ball with thereagents.

Assembly and filling of the liquid dispenser 400 is simple based on theinvention. The duckbill 416 and duckbill insert 414 are placed in thelower part of the barrel 408. The cap 406 is welded to the barrel. Thecheck ball 426 is placed, the check valve ball seat 424 is snapped andthen the quad seal 422 is inserted into the coupler 428. The stop 420and the spring 418 are inserted into the coupler 428 and the coupler 428is snapped on to the barrel 408. The barrel 408 is filled with reagentand the liquid dispenser 400 is primed. The snap cap 404, for prefilledliquid dispensers, or flip cap 402, for user fillable liquid dispensers,is placed on the top of the dispenser and the nozzle cap 458 is placedon the output of the nozzle 430 on the coupler 428.

Further, the present invention allows for easier manufacture and fillingof the reagents in the liquid dispenser 400. Previous liquid dispensersrequired gluing and sonic welding of many pieces requiring a certainlevel of skill and training. In contrast, the liquid dispenser of thepresent invention requires snapping in of pieces and only the sonicwelding of the vent 460 to the cap 406 and the cap 406 to the barrel408. Moreover, the filling of the reagents in the liquid dispenser 400is easier in the present invention. In previous liquid dispensers, theliquid dispenser is assembled except for the piston, piston guide andcap. The reservoir chamber 410 is filled with reagent. The piston isthen placed in the reservoir chamber 410 and any leftover fluid on topof the piston is evacuated. Finally, the cap is sonically welded ontothe top of the barrel 408. In the present invention, since there is nopiston in the reservoir chamber 410, there is no need to evacuate thearea on top of the piston. Instead, the cap 406 is first sonicallywelded to the barrel 408, and then the reagents are added to thereservoir chamber 410. In this manner, there are fewer steps in thefilling of the dispenser. Moreover, in the present invention, some ofthe more manufacturing sensitive parts are smaller, thereby makingmanufacturing easier. In the preferred embodiment, the material used ishigh-density polyethylene. Under these conditions, smaller parts have ahigher level of dimensional stability. Therefore, smaller components,such as the check valve ball seat 424 (which is, in the presentinvention, a separate component from the coupler 428) are able to beprocessed more consistently.

Referring to FIGS. 15A and 15B, there are shown side views of aprefilled liquid dispenser 400 and customer fillable liquid dispenser400, respectively. Both types of dispensers have barcode labels whichare read by the barcode reader, as described above. In order to allowthe customer to fill the liquid dispenser 400 with reagent, the snap cap404 is replaced by a flip cap 402 which varies in two ways from the snapcap: (1) the flip cap has an attachment to the cap; and (2) the flip caphas a protrusion 402A which acts as a thumbpad to prop open the flip cap402. In previous liquid dispensers, the liquid dispenser had to beinverted in order to prime the syringe. The customer was required tofirst fill up a transfer syringe manually upside down, push on anepindorf syringe to force fluid from the reservoir chamber 410, throughthe connecting section between the reservoir chamber 410 to the dispensechamber 412, to the dispense chamber 412. The customer had to then pumpthe plunger, at least 6 to 8 times, until fluid came out of the nozzlewhich did not have any bubbles. In the present invention, the customeropens the flip cap, fills the reservoir chamber 410, and closes the flipcap. The customer, without turning the liquid dispenser upside down,uses a typical syringe 459, as shown in FIG. 19, to prime the liquiddispenser 400. The syringe 459 has a restrictor 459A which has aninternal diameter of approximately 5 thousandths of an inch. The syringe459 is placed inside the nozzle 430 of the coupler 428 and the syringeplunger is expanded to draw liquid from the reservoir chamber 410 andthe dispense chamber 412. To prime the liquid dispenser 400 morequickly, the barrel 408 is pushed down, and is released simultaneouslywhen the syringe plunger is expanded. In this manner, there issignificantly less waste of reagent. In the previous liquid dispensers,the pumping of the plunger 6-8 times wasted reagent. In the presentliquid dispenser 400, any reagent is sucked into the syringe 459.Because the syringe 459 is clean, its contents may be placed back intothe reservoir chamber 410 through the flip cap 402.

Referring to FIG. 16A, there is shown a cutaway view of the cap 406 andvent 460 of a liquid dispenser 400. The vent is the component adjacentthe top of the cap and includes the vent area 464, vent material 466,and backing 468. The cap 406 and snap cap 404 (or flip cap 402 for userfillable liquid dispensers) are luer fitting design so that the cap 406and snap cap 404 portion which engage each other to seal the fill holeis conical. At the lower portion of the conical section of the snap cap404 is a ring or a lip 462 which is used to snap the snap cap 404 intoplace. In this manner, the snap cap 404 is pushed down until it locksinto the cap 406. The snap cap 404 has a curved section 472 which abutsagainst a curved section of the cap thereby stopping the snap cap 404 atthat point. The snap cap 404 also engages the cap 406 to form a hollowsection air space 474 which is adjacent to the vent area. This hollowsection air space 474 forms a ring, so that regardless of theorientation of the snap cap to the cap, a hollow section is adjacent tothe vent area 464 (which is approximately 70 thousandths of an inch orless). Further, the outside diameter of the snap cap 404 is slightlysmaller than the inner diameter of the cap 406 so that a small air gap476 is formed adjacent to the hollow section air space 744 to theoutside of the dispenser. The hollow air gap 474 serves as a bufferbetween the outside of the dispenser and the vent 460.

The vent 460 is used as a means to allow air to flow both into and outof the reservoir chamber 410. The vent 460 equalizes the pressure in thereservoir chamber 410 with the pressure in the atmosphere. The vent 460is a hydrophobic vent which allows air to flow through the vent whilekeeping fluid trapped inside the reservoir chamber 410. The vent iscomposed of a filter material 466 such as a teflon material with apolypropylene backing to sonically weld the vent to the cap. The ventopening or area, as described previously, is approximately 70thousandths of an inch. The pressure inside the reservoir chamber 410 isconstant, even though the level of reagent may be changing inside thereservoir chamber 410 since air is allowed to flow into the reservoirchamber 410. Moreover, some reagents produce a by-product of gas (calledoutgassing). In the event that a reagent outgasses, the hydrophobic vent460 allows gas through the vent 460, thereby avoiding any pressurebuild-up inside the reservoir chamber 410. In this manner, previousliquid dispensers which required a piston to exert force on the liquidin the reservoir chamber 410 may be removed. The piston in the previousdesign suffered from several drawbacks. First, certain reagents (such asproteins) may stick to the barrel. Additionally, the interaction betweenthe piston and the barrel relying on lubricants, certain reagents thatare composed, in part, of detergents. The detergents interfere with thelubrication between the piston and the barrel. Both effects interferewith the performance of the liquid dispenser, thereby givinginconsistent dispensing of liquid. Further, outgassing interacts withthe piston either to increase the flow out of the reservoir chamber 410or to create a compressible air gap between the piston and the mainsection of the reservoir chamber 410. Referring to FIG. 16A, there areprotrusions 470 on the inside upper portion of the cap which are used toalign the piece of vent material. The vent 460 is therefore centered ontop of that upper portion of the cap. Referring to FIG. 16B, there isshown an underside view of the vent 460. Included with the vent 460 is aplatform 468 for the vent 460, star-shaped in design, which holds thevent 460 flat. When air is passing through the vent 460, particularlywhen outgassing, the vent 460 has a tendency to flex which may damagethe teflon in the vent. In order to minimize flexing of the vent 460,the platform 468 is adjacent to the vent. Therefore, the surface area ofthe vent may still be relatively large but still have a grid support tostabilize the vent 460 during outgassing. The platform 466 isstar-shaped due to ease of molding.

In an alternative embodiment, as shown in FIG. 16C, the vent may besubstituted with a bi-directtional valve 478 or bi-directtional duckbill(or two valves or two duckbills) as another means by which to allow airto flow into and out of the reservoir chamber 410. The bi-directtionalvalve 478 has a bi-directional valve insert 480 for placement of thebi-directional valve 478. The bi-directtional valve 478 also has ahydrophobic layer which allows air to flow through the bi-directionalvalve 478 while keeping fluid trapped inside the reservoir chamber 410.In one direction (air flowing into the reservoir chamber 410), thebi-directtional duckbill 478 has a low cracking pressure, in order toequalize the pressure in the reservoir chamber 410 when liquid isdispensed. In the second direction (air flowing out of the reservoirchamber 410), the bi-directtional duckbill 478 has a high crackingpressure, in order to alleviate any pressure due to outgassing. Thebi-directional duckbill 478 allows air to flow through while keepingfluid trapped inside the reservoir chamber 410. Therefore, thebi-directtional duckbill 478 allows air to flow into and out of thereservoir chamber 410 and allows for equalization of the pressure. Inpractice, a bi-directional duckbill 478 may have less refinement interms of control when compared to two uni-directtional duckbills. Ifadditional refinement is required, the bi-directtional duckbill 478 maybe replaced by two uni-directtional duckbills. Moreover, whenintegrating the two uni-directtional duckbill, with anotheruni-directtional duckbill at the bottom of the barrel, the systembecomes a three duckbill system. In this configuration, the duckbillthat releases to atmosphere has the lowest cracking pressure, theduckbill that allows air into the reservoir chamber has the highestcracking pressure, and the duckbill 416 that is down in the barrel has amedium cracking pressure.

Pressure differentials caused by outflow of liquid from the reservoirchamber 410, as discussed previously, may make the dispensing of liquiddifficult. Further, in certain instances, outgassing may not interferewith the operation of the liquid dispenser 400. Therefore, in anotherembodiment, as shown in FIG. 16D, the vent 460 may be substituted with auni-directtional valve or duckbill 482, with a duckbill valve insert484. In the one direction (air flowing into the reservoir chamber 410),the uni-directtional duckbill 482 has a low cracking pressure toalleviate pressure due to outflow of liquid from the reservoir chamber410. In this embodiment, vent material is not required since the air isflowing only into the reservoir chamber.

In a further embodiment, as shown in FIG. 16E, the vent opening 464 maybe reduced to approximately 10 thousandths of an inch (from 70thousandths of an inch) and the snap cap 404, for prefilled liquiddispensers, or the flip cap 402, for user tillable liquid dispensers,may be modified to include a seal 488 where the snap cap 404 or flip cap402 engages the cap 406. Thus, this alternative embodiment does not havea gap 476 between the snap cap 404 (or flip cap 402) and the cap 406,but instead includes a seal 488. In order for the flow of air into orout of the reservoir chamber 410, there is an opening 486, such as a pinhole or a second vent, placed in the top of the snap cap 404 (or flipcap 402) which is adjacent to the hollow region 474 formed between thesnap cap 404 and the cap 406.

Referring to FIG. 17A, there is shown a cutaway view of the lowerportion of the barrel 408, duckbill 416, duckbill insert 414, quad seal422, check ball 426, check valve ball seat 424 and coupler 428 of aliquid dispenser 400. The barrel 408 has protrusions 408A which matewith the coupler in order to maintain the position of the barrel 408 onthe upstroke. Otherwise, if the spring pushes the barrel 408 upward toohigh, the seal, as provided by the quad seal 422, may be broken therebycreating an air path and causing the liquid dispenser 400 to lose prime.The barrel 408 also has a flange 408B which mates with the stop 420 onthe downstroke. The barrel 408 also has a pocket 408C, where theduckbill insert 414 is inserted. This pocket acts as a funnel so that nopuddles are formed at the bottom of the barrel 408 at the interactionpoint with the duckbill 416 or duckbill insert 414, thereby minimizingwaste. The barrel 408 also has at its lower portion a piston 454 bywhich liquid is expelled in the dispenser 400. At the lower portion ofFIG. 17A is a nozzle cap 458 for engagement with the nozzle 430 of thecoupler 428. The nozzle cap 454 and nozzle 430 are matched using a luerfitting design in order to be a fluid tight seal. Referring to FIG. 17B,there is shown a cutaway view of the lower portion of the barrel,duckbill, and duckbill insert of a liquid dispenser. Referring to FIG.17C, there is shown a cutaway view of the quad seal of a liquiddispenser.

Referring to FIG. 17A, there is shown a cutaway view of the coupler 428.The coupler 428 has grooves 428B in which the check valve ball seat 424snaps. The grooves 428B act to prevent any leakage of fluid downward orair upward through the walls of the check valve ball seat 424 and thecoupler wall. The coupler 428 also has protrusions 428C, or wings, whichensure that the dispenser is aligned on the reagent tray. For example,if the dispenser is misaligned, the dispense cylinder may not engage thedispenser properly. The coupler also has stabilizing bumps 428D whichreduce any rocking back and forth of the liquid dispenser 400.

In another embodiment of the invention, there is provided a means bywhich to transfer data from the manufacturer to the customer. Themanufacturer uses a manufacturing database in order to maintain a recordof reagents, master lots, and serial numbers for kits and dispensers.The manufacturing database is an Interbase (client/server) databasecontained in a single file. The manufacturing database definitionconsists of domains, tables, views, and triggers. Domains define thevariable types and requirements used in tables. Tables define the datathat is stored for each record. Views (meta-tables) are accessed astables but do not contain data. The views collect data from tables.Triggers are programs that are executed on the Interbase server inresponse to defined events.

Information is stored on the database to define kits (which containseveral dispensers) or single dispensers. Each package, whether a kit ora dispenser, will include a barcode identifying the contents. For kits,the barcode will contain the part number, master lot number and serialnumber. For single dispensers, the barcode will contain the part number,lot number and serial number. Serial numbers are assigned to kitssequentially for each master lot starting at 1 (i.e., the first kitcreated from each master lot will be assigned serial #1). The packagebarcodes are separate from the bar codes that appear on the individualdispensers within the package. In particular, in the case of a singledispenser package, the serial on the package barcode label need notmatch the serial number of the single dispenser contained in thepackage.

The barcode is encoded with the Code 128 Symbology. The plain textinterpretation of the barcode is to appear as standard ASCII text belowthe barcode. This allows for operator verification of the data obtainedby scanning. The three fields on the package label will be fixed inlength and combined into a single barcode by concatenation.

Referring to FIG. 20, there is shown a block diagram of themanufacturer's system for programming an external memory device. Themanufacturing computer 500 is a typical personal computer, with aprocessor 502 including a comparator 504, and memory 506 including RAM508 and ROM 510. As described subsequently, the processor 502 is incommunication with a barcode scanner 512 and a memory device 516 such asan EPROM (erasable programmable read only memory). In the preferredembodiment, the processor 502 is in communication with the memory device516 via a memory wand 514, as described subsequently.

As described in Appendix A, there is software which implements theacquisition of data from registration tables, and stores the data intoan external memory device. Referring to FIGS. 21A-B, there is shown aflow chart for updating the forms on the manufacturers database. Theforms are used as templates for the manufacturing database for kits,dispensers, dispenser models, etc. which are later entered. The formsinclude reagents, dispenser models, dispensers, kits and filled kits.For example, in the reagent form, data about a particular reagent, suchas the reagent name, group name, etc. may be entered. The dispensermodels include user fillable and prefillable dispensers. Referring toFIG. 20, the operator is asked if he or she wishes to update the reagentform 522. If so, the manufacturing database determines if the reagentform is new or old 524. If new, a blank template is displayed for theoperator to enter data 526. If a reagent form is to be modified, thereagent template is displayed 528, 530. The contents are entered ormodified and the data saved to the database 532, 534. Likewise, theforms may be modified for the dispenser form, which includes data on thepart number, reagent, code, whether the dispenser is prefillable, thedispenser model, whether the reagent is active, etc. The operator isprompted whether the form is new 540, and if new a blank template isdisplayed 542. If old, the previous dispenser forms are displayed 544and the user selects a form 546. Data is entered 548 and saved 550. Theforms may be modified for the kit configuration as well. The kitconfiguration includes data on the dispensers included in a kit sent tothe end user. This information includes the part number, the descriptionof the kit, whether the dispensers in the kit are active, the number ofreagents in the kit, and data on the dispensers in the kit. The operatoris prompted whether the form is new 556, and if new a blank template isdisplayed 558. If old, the previous dispenser forms are displayed 560and the user selects a form 562. Data is entered 564 and saved 566. Theforms interact with one another for ease of updating. For example, ifthe dispenser model is modified, the dispenser form, which is dependenton the dispenser model, is modified as well. Further, if the dispenseris modified, so is the kit configuration, which in turn depends on thedispenser.

The updating the master lot and entering data into the memory device isshown in the flow chart in FIGS. 22A-B. The master lots form supportsassignment of master lot numbers to predefined kits, as well as lotnumbers and expiration dates to each of the dispensers in the kit. Theexpiration date of the kit is the earliest of the expiration dates ofthe dispensers in that kit. If the operator wishes to update the masterlot 570, the manufacturing database determines if the master lot is oldor new 572. If new, the list of kits is displayed 574 and a blanktemplate for the user selected kit 576. If old, the previous master lotsis listed 578 and the user selected master lot is displayed 580. Data isentered for the master lot 582 and then saved 584.

When the operator wishes to fill the memory device 588, in the preferredembodiment, the memory device 576 is an EPROM such as the DallasSemiconductor DS1985 F5 16 Kbit add-only touch memory device. Othermemory devices may be used to store the information and allow the enduser to retrieve the information. First, the package bar code labels arescanned 590. A Welsh Allyn Scanteam 5400/5700 hand held scanner is used.The scanner need only be configured once to identify the hardwareplatform and bar code symbology. The scanner is programmed to send a `!`as a prefix character and also a `!` as a suffix character. The prefixis used to differentiate input from the scanner from input from thekeyboard. The suffix is used to identify completion of acquisition.

Based on the information scanned from the package, the kit type isdetermined based on the information in the kit forms 592. The barcodesfor each of the dispensers in the package is then scanned 594.Information in the kit form is compared with the information scanned in596. For example, the number of dispensers in the package is checked. Ifthe number is too high or too low, the user is notified and the memorydevice is not programmed. Further, if the type of the dispensers in thepackage does not match the type of dispensers in the kit form, the useris notified and the memory device is not programmed. This is one of themethods to increase the quality control. If there was an error in thepackaging of the package, (e.g., an incorrect dispenser was placed inthe package), the user will be notified to correct the problem 598.

If the number and type of dispensers are correct, the database collectsall data necessary for the current kit and dispensers 602. A touch₋₋memory object is created which contains the form in which the memorywill be stored 604. The data for the current kit and dispensers iswritten to the touch₋₋ memory object buffers 606. Finally, the touch₋₋memory object buffers are transferred to the touch memory device 608. Inorder to program or read the touch memory device, a probe (DallasSemiconductor DS9092GT) mounted in a hand held wand 514 is used. Thiswand 514 is attached to the serial port of the manufacturing computer500 programming the touch memory device 516 through a DallasSemiconductor DS9097 or DS9097E serial port (DB-25) adapter.

At the end user, the kit or single dispenser is accompanied by thememory device. Referring to FIG. 23, there is shown a flow chart fordownloading data from a memory device to the host system. The probe isfirst connected to the touch memory device 612. The contents of thetouch memory device are downloaded to the host computer 614 anddisplayed to the user 616. It is then determined whether the touchmemory device has been downloaded previously 618. This is done based onthe contents of the touch memory device. If the memory contents werepreviously downloaded, a flag is set in the memory contents. Therefore,this kit has already been "used" and therefore should not bereprocessed. The user is prompted whether he or she wants to update theuser's databases with the kit/dispenser data 624. If so, the probe isreconnected to the touch memory device 626, verified that it is the sametouch memory device by comparing the current downloading with theprevious download of data 630. The flag indicating that the touch memorydevice is "used" is set inside the memory device 628. In this manner, amemory device may be downloaded only once for purposes of security. Thecontents of the user's databases are updated with information containedin the touch memory device such as name, type, group, lot,characteristics, quantity, expiration dates for the reagents, and theusable life, maximum volume, dead volume and registration date for thedispenser 632.

Information in the touch memory device is used to update various tablescontained in the user's database including the registration, receive andquality control tables for use by the operator. There are five differenttypes of things that each have registration, receive and quality controltables: (1) antibodies; (2) reagents; (3) kits; (4) consumables and (5)control slides. Antibodies are chemicals that have living cells withinwhich attach to the patient's tissue. Reagents are non-antibodychemicals which typically contain no living material. Kits, as describedabove, contain various combinations of dispensers. Consumables arematerials such as the Liquid Coverslip™, wash buffer, etc. Each of thesematerials are regulated in different manners, thereby requiringdifferent information contained within the registration, receive andquality control tables. For example, since antibodies are livingmaterial, they are regulated more highly and therefore requireadditional information in the tables.

The registration table contains the background information for thespecific material. For example, the registration table contains the nameof the material (antibody, reagent, kit, or consumable), themanufacturer, the clone number (antibody) and other informationdescribing the material. This table is updated only when the material isfirst received. The receive table is a table which records each timewhen a certain material is received and the expiration date of thatmaterial as well as other information specific to this lot of material.Therefore, while the registration table may describe a specificantibody, the receive table will describe on which dates each dispenserof an antibody was received, the expiration date for the antibody, andthe lot number. This information is used not only to generate reportswhich are required by regulation, but also to check for the expirationdate of the chemical during a run, which is described subsequently. Thequality control table records when a particular chemical was validated.Regulations require that when a new chemical or when a new lot for apreviously received chemical is received, the lab must check to makesure the material performs in the expected manner (i.e., the materialwas processed correctly and not damaged in shipment). To determine ifthe material is "acceptable" to use in testing on patient tissuesamples, end users have tissue that is known to test positive withundamaged reagents. The quality control table will track whether thechemical was tested for effectiveness and which tissue sample was usedto test the chemical. In this manner, the tables, which are generated inlarge part by information from the touch memory, allow the end user tocomply with regulation.

Other tables are used during a run which provides for better qualityassurance in testing. For example, there is a dispenser table whichcontains, for each dispenser, the pertinent information for qualityassurance during a run. For example, for each dispenser with acorresponding barcode, the table contains the expiration date, and thenumber of drops in the dispenser.

Referring to FIGS. 24A-B, there is shown a flow chart for updating theregistration, receive and quality control tables on the host computerfor use by the operator. Dispenser/kit information is read from thetouch memory device. The computer determines if the touch memory deviceholds kit information 638. If so, the touch memory device searches theregistration table to determine if the kit was previously received 640.If the kit was not received previously, the registration table must beupdated with the kit registration information such as manufacturer andcatalog number 642. The individual dispenser information within the kitis updated in the dispenser table including the serial number, productcode, master lot number, total dispenses (by number of drops) andexpiration date 644. The receive table is updated to include the receivedate, lot number, serial number, and receiver 646. The quality controltable is searched to determine if there is an entry in the table forthis kit's lot number (i.e., if this is a new kit or a new kit lotnumber) 648. If the kit lot number has already been quality controltested, the user is informed that this has already been done 650. Ifnot, the user is informed that a quality control test must be performed676. In an alternative embodiment, a separate look-up table of knowntissue samples used to test the effectiveness of a chemical received isarchived. The known tissue samples are suggested to the user to test theeffectiveness of the chemical received in order to update the qualitycontrol table.

The computer determines if the touch memory device holds prefilledantibody information 652. If so, the touch memory device searches theregistration table to determine if the antibody information waspreviously received 654. If the antibody information was not receivedpreviously, the registration table must be updated with the antibodyregistration information such as name, manufacturer, catalog number,clone, 1 mg subclass, presentation, and species 656. The individualdispenser information is updated in the dispenser table including theserial number, product code, master lot number, total dispenses (bynumber of drops) and expiration date 658. The receive table is updatedto include the receive date, lot number, serial number, and receiver660. The quality control table is searched to determine if there is anentry in the table for this antibody lot number (i.e., if this is a newantibody or a new antibody lot number) 662. If the antibody lot numberhas already been quality control tested, the user is informed that thishas already been done 650. If not, the user is informed that a qualitycontrol test must be performed 676.

The computer determines if the touch memory device holds prefilledreagent information 664. If so, the touch memory device searches theregistration table to determine if the reagent information waspreviously received 666. If the reagent information was not receivedpreviously, the registration table must be updated with the reagentregistration information such as name, manufacturer, and catalog number668. The individual dispenser information is updated in the dispensertable including the serial number, product code, master lot number,total dispenses (by number of drops) and expiration date 670. Thereceive table is updated to include the receive date, lot number, serialnumber, and receiver 672. The quality control table is searched todetermine if there is an entry in the table for this reagent lot number(i.e., if this is a new reagent or new reagent lot number) 674. If thereagent lot number has already been quality control tested, the user isinformed that this has already been done 650. If not, the user isinformed that a quality control test must be performed 676.

The computer determines if the touch memory device holds customerfillable dispenser information 678. If so, the individual dispenserinformation is input including the serial number, product code, masterlot number, total dispenses, expiration date, dispenser drop life,maximum volume, dead volume and priming waste 680. In an alternativeembodiment, the user is prompted to input the amount of liquid, inmilliliters is placed in the dispenser. This amount in milliliters isconverted into a number of drops and stored in the table. The user may,at a later time, fill the user fillable dispenser and, at that latertime, update the dispenser table with the amount of liquid put in thedispenser.

There are a series of checks using the information from the touchmemory. Referring to FIG. 25, there is shown a flow chart fordetermining if the kit/dispensers for use by the operator is the correctnumber and correct complement, in an alternate embodiment of theinvention. The kit barcode information from the touch memory is read todetermine the type of kit and dispensers contained in the package 682,684. Based on this barcode information, there is a look-up table whichdescribes the number of reagents in the kit and the type or complementof reagents in the kit. This historical information in the look-up tableis compared with what was actually sent in the package. If there is adiscrepancy as to the number of dispensers in the kit or in the type ofreagents in the kit 686, 688, the user is notified and the user'sdatabase is not updated with the kit barcode information 690. In thismanner, the quality control may be increased by checking whether theproper dispensers were included in the kit.

After the downloading of the data, the host device 32 and remote devices166 may execute a run. As described previously, the host device 32 andremote devices 166 are modular in design in that higher level systemfunctions are handled by the host whereas the execution of the steps forstaining is performed by the remote devices 166. This modularity ofdesign utilizing a personal computer as a host device 32 is beneficialin several respects. First, the host computer can be used to start runson other remote devices 166. Second, the host device 32 can periodicallyupdate the software more efficiently on the remote device 166 based onupgrades in the operating system. For example, the lowest level code inthe remote devices 166, which handles the basic input and output for theremote device 166 and the execution of programs, may be updated based onchanges in error messaging, changes in output device design (such asdifferent types of valves), and changes in the messaging protocolsbetween the host and the remote. Third, the modularity multiplies thenumber of staining modules which may be run by a single machine. Fourth,since the host device 32 is comprised, in the preferred embodiment, of apersonal computer, the host machine may be easily upwardly compatible,as opposed to previous standalone staining modules. Further, thepersonal computer can be integrated with a network environment tointegrate with other computers. For example, there is a trend inhospitals to standardize the computer hardware used and to interconnectthe computer hardware. The host device 32 may be connected to a hospitalnetwork, receiving commands from other computers on the network toexecute a staining run, described subsequently, or sending results of arun to another computer on the network. Fifth, the host device 32 mayserve as a platform through which various staining modules may beintegrated. For example, there are various types of staining modules,some which use dispensers versus vials, some which use horizontal slidetrays versus vertical slide trays, etc. The host device 32 may beintegrated with a variety of staining modules, downloading programs tothe different modules, described subsequently, depending on theparticular configuration of the module. Sixth, the remote devices 166,as a modular piece in the automated biological reaction system, may beserviced more easily. Instead of having a large machine dedicated tostaining, the remote device 166 is smaller and can be shipped throughthe mail easily. In this manner, when an end user has difficulty with aremote device 166, the user may receive a second remote device throughthe mail, and send the faulty remote device back to be fixed. Therefore,the user need not rely on on-site maintenance for the remote device, andthe attendant cost associated with on-site maintenance.

The host may execute three different types of runs. The first run is atest run, which is described subsequently. The second run is a systemrun, whereby the remote device 166 reads the barcodes for the slides orthe dispensers, or other non-staining functions required to setup astaining run. The third run is a staining run whereby the remote device166 stains the slides. The second and third runs are described in FIGS.26A-G. When executing a run, the host downloads a sequence of steps in arun program to the remote device 166. The run program is comprised oftwo separate pieces: (1) a main program (defined as macro 0); and (2)subroutines (defined as macros 1-255). The main program is can becomposed of, but not limited to, calls to the subroutines. Therefore,the entire length of the run program through calls to subroutines isless than a line by line execution of the entire program. For example,if a subroutine is called 50 times, the main program calls thesubroutine 50 times rather than downloading a program which includes thecode for the subroutine 50 times. In addition, the subroutines aredefined by a programming language of thirty-one low-level commands whichperform basic functions on the remote such as checking the timer,turning on an output such as a valve or a heater, or moving thecarousel. When downloading the run program, the macros are downloaded asneeded to execute a single run.

In addition to downloading a run program, the host device 32 downloadsthe sensor monitoring and control logic called the run rules. Thisprogram is made up of a series of continuous checks that must be doneduring the execution of the run program. As discussed previously, one ofthe checks is the upper and lower limit of the temperature of theslides. If, during a run, the environmental temperature is below thelower limit, as indicated by slide temperature monitoring sensor, theslide heater is turned on. Likewise, if the environmental temperature isabove the upper limit, as indicated by slide temperature monitoringsensor, the slide heater is turned off. Another run rule relates to theopening of a system door. Additional run rules relate to the environmentin which the remote device 166 executes the run. If any of the sensorsare outside of the boundaries sent by the run rules, the remote device166 sends a message which is retrieved by the host device 32. Asdiscussed generally in FIG. 5C with respect to placing messages in thequeue, the first priority is the execution of the steps in the runprogram. In addition to this, where spare processing is available, thehost device 32 polls the remote device 166 for status. The host device32 does this approximately every 11/2 seconds to receive the status ofthe remote device 166 including the current temperature of the remotedevice 166, current step number being processed in the run program,elapsed time of the run, and any errors during the run. The host makes arecord of any anomalies during the remote device run and prints thefinal report at the end of the run.

An example of a staining run is shown in flow chart form in FIGS. 26A-G.The first run is a system run to read the barcode on the slides. Inexecuting this run, the host device 32 downloads a run program and therun rules 696. The remote device reads a barcode 698, stores the barcodein a file 699 to be used subsequently, then waits for the host toretrieve the barcode and retrigger the remote to read another barcode onthe slide 700. The remote device 166 does this until the last slide isread 702. The host then downloads the run program and run rules for thesecond system run, which concerns the reading of the barcodes on thedispensers 704. Similar to the first system run, the remote device 166reads a barcode 706, stores the barcode in a file 707 to be usedsubsequently, then waits for the host to retrieve the barcode andretrigger the remote to read another barcode on the dispenser 708. Theremote device 166 does this until the last dispenser is read 710.

The host device 32 then reads the slide bar codes already stored in thefile 712. If the number of entries is the file is different from thenumber previously entered by the operator, an error message is generated730. This is done since the barcode reader, at times, may not read oneof the barcodes on the slide. In that case, the run is stopped. The hostdevice then reads the barcodes for the reagents already stored in thefile 716. Based on the barcodes, the host device loads the protocols forthe slides from the database. In order to simplify the procedure, eachbarcode on a slide is standardized. For example, if the staining for theslide is to test for prostate cancer, a particular barcode is placed onthat slide which is used for every slide which is to be tested forprostate cancer. For each specific test, there are a series of macroswhich are to be executed by the remote device 166. In the case of thetest for prostate cancer, a look-up table indicates the series of stepsor macros corresponding to the particular barcode designated as a testfor prostate cancer. As discussed previously, there are macros from 1 to255 which define basic operations of the remote device 166. For thespecific task of testing for prostate cancer, the lookup table includesall the necessary macros, in the proper sequence, to perform the test.Based on these macros, the host device 32 determines the types ofreagents and amount of drops required to execute the steps 714.Moreover, in creating the run program, calls to the macros are includedin macro 0 and macros 1-255 which are to be called are included aftermacro 0. The protocols correspond to the user defined options for aparticular staining run. In the case of the example for testing forprostate cancer, the options include the type of reagents, the number ofdrops, etc.

All the protocols are loaded and determined if they exist in thedatabase. If so, the host device loads data from the dispense table 720and determines if all of the dispensers are present and loaded 722. Ifso, the recipes are loaded from the database 724. In contrast to theprotocols, the recipes define steps which the user does not control. Forexample, turning on valves, heating the slides, etc. are operationswhich the users cannot alter. The host device 32 then verifies that therecipes can be run together 726. For example, if there are two recipeswhich dictate the temperature of the slides (where the slides are inclose proximity), and the temperatures are different, the two recipescannot be executed; therefore, and error message is generated 730. Thesteps for the run is then computed 728. Because there are several slidesbeing tested at the wheel at once, and each slide has a series of stepsassociated with it, the host device generates the run program which canexecute all the steps for all of the slides. The host device isconstrained by being able, for example, to mix with the vortex mixers ata certain station on the slide carousel, to dual rinse at a certainstation, to add the volume adjust, etc. Based on these constraints, therun program is generated which tells the remote to execute the steps inthe proper sequence at the proper station 728.

The host device determines if there are multiple dispensers of the samereagent 732. If so, an error message is generated since, for qualitycontrol purposes, dispensers from the same kit may only be used in arun. The host device then determines if this is a titration run 734. Ina user filled dispenser, the user may wish to test varyingconcentrations of reagent in the liquid dispenser. If so, the userexecutes a titration run whereby the user is allow, via the program, tostop the run in the middle and titrate different concentrations. Theamount of time for the titrations must be short enough so that the slidewill not dry out 736. Otherwise, an error message is generated 750. Themacro functions are loaded from a database for the run 738 anddetermined if all the macro functions loaded properly 740. The hostdevice 32 determines, based on the dispenser table, whether any of thedispensers are past the expiration date 742. If so, the operator isnotified 744. Similarly, the dispenser table is checked to determine ifthe dispensers have sufficient liquid to conduct the run 746. If not,the operator is notified to refill or replace the dispensers 748.Optionally, quality control can be checked to determine if all of thedispensers have been tested under quality control protocols 752.

Therefore, the host device 32 looks up in the dispenser table 716,described in FIGS. 24A-B, to determine if the reagents necessary (1) arepast their expiration date; (2) are present to perform the run; (3) haveenough drops in the dispensers to execute the run; or, optionally, (4)have been tested for quality control. If any of the first threeconditions fail, the run cannot be executed and the operator is notified(i.e., one of the dispensers is past its expiration date, one of thedispensers is missing, or one of the dispensers is low on liquid).

Optionally, for quality control purposes, the dispenser table issearched to determine if quality control was performed on the dispenser752. If it has not yet performed, the operator is notified 754 and askedif he or she wishes to proceed 756. If the operator wishes to proceed,he or she must enter his or her name, the date and time in order tocontinue the run 758. Finally, when the run is executed, the informationentered by the operator is included in the history of the run, describedpreviously, to indicate that at least one of the dispensers had not beentested in compliance with the regulations, but that the run wasperformed anyway 760. In this manner, the quality of the run may beincreased due to monitoring of the dispensers used in the testing of thetissue samples. The host device 32 then saves the dispense data for therun to a database 762 and merges the run rules, which determine theoperating environment of the run, together for the run 764. The hostdevice 32 downloads the run program and the run rules for the currentstaining procedure 766. The host device 32 commands the remote to runthe steps and to run the checks or the run rules 768. As discussedpreviously, the host device 32 periodically checks the status of theremote device 770. After the remote device 166 finishes execution of therun program 772, the host device 32 compiles the history of the run andstores the information sent from the remote 774.

The host device 32 also communicates with the remote devices 166 byreading and writing information regarding the operation of the remotedevices 166. For example, the host device 32 downloads a commandindicating to the remote device the amount of time (in 10's ofmilliseconds) the valve 248G for the volume adjust line is on. Thisvalue is stored in non-volatile RAM on the remote device 166. Further,the host device 32 may poll the remote device to send its stored valuefor the volume adjust time stored in non-volatile RAM. Otherinformation, such as the slide temperature monitoring sensor 68, bufferheater temperature sensor 66 and system pressure transducer 290, asdescribed in FIG. 6A, may be read by the host device 32 and may becalibrated by the host device 32. When reading the sensor informationfrom the remote device 166, the current calibration data is sent back tothe host. Calibration data is used to adjust for constant errorsinherent in each temperature sensor and pressure transducer. In order tocorrect for errors, the host device writes to the remote. For example,when calibrating the pressure sensor, the host device 32 commands theremote device to perform span calibration of the system pressuretransducer 290 at the preset pressure of 13.0 psi. The remote device 166registers the current raw pressure as the 13.0 psi analog to digitalpoint.

Referring to FIG. 27, there is shown a flow chart of the testing run forthe remote device. One of the commands or steps downloaded to the remotedevice is a test command 776. The remote processes the commands in therun program 778 until the remote device 166 receives the test command780. The remote device 166 then waits until a button 295 is pressed onthe remote device 782, as described in reference to FIG. 6A. When thebutton 295 is pressed, the remote device executes the previous command,and then waits for the button 295 to be depressed again. In this manner,the operator may test individual steps or commands by pressing thebutton 295 and re-executing the previous command. In an alternativeembodiment, the remote device interprets the test mode as a means bywhich to single step through the program. Every time the button 295 ispressed, the remote device 166 executes a command. In this manner, theoperator may step through the run program and determine if there are anyerrors in the sequence of steps.

From the foregoing detailed description, it will be appreciated thatnumerous changes and modifications can be made to the aspects of theinvention without departure from the true spirit and scope of theinvention. This true spirit and scope of the invention is defined by theappended claims, to be interpreted in light of the foregoingspecification.

We claim:
 1. A method of placing a consistent amount of fluid on a slidein an automated biological reaction apparatus, the automated biologicalreaction apparatus having at least one rinse station, the rinse stationcomprising a rinse station nozzle positioned for directing a stream offluid onto the slide, the rinse station nozzle connected to tubing whichis connected to at least one valve, the valve connected to a bottlecontaining fluid, the valve controlling the flow of fluid from thebottle to the nozzle, the method comprising the steps of:pressurizingthe tubing with a predetermined amount of pressure; turning on and offthe valve for supplying fluid to the nozzle at least one time therebycausing a wave effect in the tubing wherein the pressure in the tubingvaries from the predetermined amount of pressure, the time betweenturning on and turning off the valve being a first predetermined time;delaying until the wave effect wave effect in the tubing is lessened sothat the pressure in the tubing is substantially equal to thepredetermined amount of pressure; turning on the valve to begin aconsistency pulse and directing a stream of fluid onto the slide;waiting for a second predetermined time, the second predetermined timebeing greater than the first predetermined time; and turning off thevalve to end the consistency pulse.
 2. A method as claimed in claim 1wherein the stream of fluid directed onto forms an angle with thehorizontal, the angle being less than 35 degrees.
 3. A method as claimedin claim 1 wherein the step of waiting includes waiting at least 300mSec.
 4. A method as claimed in claim 1 further comprising the stepsof:providing in the rinse station a second valve, the second valveconnected to the bottle containing fluid, the second valve controllingthe flow of fluid from the bottle to the nozzle; turning on the secondvalve for supplying fluid to the nozzle substantially simultaneouslywith the step of turning on the valve to begin a consistency pulse, anddirecting a stream of fluid onto the slide; waiting for the secondpredetermined time; and turning off the second valve.
 5. A method asclaimed in claim 1 further comprising the steps of:providing a volumeadjust station in the automated biological reaction apparatus, thevolume adjust station comprising at least one volume adjust nozzlepositioned above the slide for depositing fluid onto the slide, thevolume adjust nozzle connected to tubing which is connected to a volumeadjust valve, the volume adjust valve connected to a volume adjustbottle containing fluid, the volume adjust valve controlling the flow offluid from the bottle to the volume adjust nozzle; turning on the volumeadjust valve and directing a stream of fluid which is substantiallyperpendicular to the slide after turning off the valve for supplyingfluid to the volume adjust nozzle at the rinse station; waiting a thirdpredetermined amount of time; and turning off the volume adjust valvefor supplying fluid to the volume adjust nozzle.
 6. A method as claimedin claim 5 further comprising the step of restricting the flow of fluidwhich is flowing from the volume adjust valve.
 7. A method as claimed inclaim 1 wherein the rinse station further comprises a second rinsestation nozzle positioned for directing a second stream of fluid ontothe slide, the second rinse station nozzle connected to tubing which isconnected to a second rinse station valve, the second rinse stationvalve connected to the bottle containing fluid, the second rinse stationvalve controlling the flow of fluid from the bottle to the nozzle, andfurther comprising the steps of:turning on and off the second rinsestation valve for supplying fluid to the second rinse station nozzle,after the step of turning on and off the valve for supplying fluid tothe nozzle, the time between turning on and turning off the second rinsestation valve being the first predetermined time; repeating the steps ofturning on and off the valve and turning on and off the second rinsestation valve.
 8. An automated biological reaction apparatuscomprising:a slide support carousel; drive means engaging the slidesupport carousel for moving the slide support carousel; a reagentdelivery system for applying a predetermined quantity of reagent to oneof the slides by movement of the slide support carousel in a reagentdelivery zone; a heat zone for heating samples on the slide supportcarousel; a rinse station, the rinse station comprising a first nozzle,a first valve connected to the first nozzle through tubing, the firstvalve connected to a bottle containing fluid; means for pressurizing thetubing with a predetermined amount of pressure; and controller connectedto the first valve, the controller including a look-up table having avalue a first predetermined amount of time and a second predeterminedamount of time, wherein the controller delays before opening the firstvalve for the first predetermined amount of time in order for thepressure in the tubing to be substantially equal to the predeterminedamount of pressure and wherein the controller opens the first valve forthe second predetermined amount of time.
 9. An automated biologicalreaction apparatus as claimed in claim 8 wherein the rinse stationfurther comprises a second valve, the second valve connected to thefirst nozzle through tubing, the second valve connected to the bottlecontaining fluid, the controller connected to the second valve andwherein the controller controls the flow of fluid from the bottle to thefirst nozzle via the operation of the second valve, the controlleropening the second valve substantially simultaneously with the openingof the first valve until the pressure is substantially equal in thetubing.
 10. An automated biological reaction apparatus as claimed inclaim 9 wherein the rinse station further comprises a second nozzle, athird valve connected to the second nozzle through tubing, the thirdvalve connected to the bottle containing fluid and connected to thecontroller, a stream of fluid directed from the second nozzle being atan angle with the horizontal greater than the stream of fluid directedfrom the first nozzle.
 11. An automated biological reaction apparatus asclaimed in claim 9 further comprising a volume adjust station connectedto the controller, the volume adjust station comprising a volume adjustnozzle positioned above the slide for depositing fluid substantiallyperpendicularly onto the slide, the nozzle connected to tubing which isconnected to a volume adjust valve, the volume adjust valve connected tothe bottle containing fluid, the volume adjust valve controlling theflow of fluid from the bottle to the volume adjust nozzle.